| stream - a file stream opened for reading, or a TCP stream |
|
Reads one byte from a file or stream and returns it as a value from 0 to 255. A byte is the smallest unit you can read - 8 bits, holding 0 to 255. The result is always unsigned: a -1 stored with WriteByte comes back as 255, because only the low 8 bits of the original number were kept. Since text characters are single bytes, ReadByte can also walk through a file character by character (Chr$ turns the value back into a character). Reading past the end of the file is not an error - you just get 0 - so use Eof to know when to stop. On a TCP stream the call waits until a byte arrives; check ReadAvail first if you cannot afford to wait. See also: WriteByte, ReadShort, ReadInt, Eof, ReadAvail. |
; ReadByte Example
; ----------------
; Save a few bytes so there is something to read
file=WriteFile("demo_bytes.dat")
WriteByte file,65
WriteByte file,100
WriteByte file,255
CloseFile file
; ReadByte reads a single byte and always returns 0 to 255
file=ReadFile("demo_bytes.dat")
a=ReadByte(file)
b=ReadByte(file)
c=ReadByte(file)
CloseFile file
Print "Bytes read from demo_bytes.dat:"
Print " "+a+" (the ASCII code for "+Chr$(a)+")"
Print " "+b
Print " "+c+" (the largest value a byte can hold)"
; Clean up the demo file
DeleteFile "demo_bytes.dat"
Print "Deleted demo_bytes.dat"
Print ""
Print "Press any key to close the example"
WaitKey
End